WSJ:
People hoping that the approach of autumn will mean fewer allergies, may want to prepare for some sneezing with their leaf-raking.
For many people, allergic reactions go into overdrive late summer and into fall because pollen counts soar. Mold counts rise, too, thanks largely to wet leaves sitting on the ground, a terrific breeding situation for mold spores.
While many popular garden plants are insect-pollinated—often with showy flowers that attract pollinators, and bearing heavier, stickier pollen grains—it is the wind-pollinated plants that cause the most problems for allergy sufferers, says Susan Littlefield, horticulturist for the National Gardening Association.